The present invention relates to a directional control valve component assembly of several directional control valves adapted to be electromagnetically shifted independently of one another, which are plugged-in or inserted into plug-in receptacles or sockets of a common base element and which separate from one another or connect with one another fluidic feed and load connection paths provided in the base element and terminating in the plug-in receptacles, whereby the plug-in receptacles are fluidically sealed off by the directional control valves when the latter are inserted or plugged-in into the plug-in receptacles, and whereby the feed and load connection paths exit on a surface of the base element.
A component assembly of the aforementioned type is disclosed in the prior patent application P No. 36 34 349.8-14 (DE-PS No. 36 34 349).
In this prior art patent, the individual directional control valves are clamped-in between a base element and a cover plate. An electric printed circuit board, connected with the solenoid windings of the directional control valves for the current distribution, is arranged outside of the clamped-in area of the directional control valves and can be connected only after the completed installation of the mechanical parts of the component group.
Air-conditioning systems are used in motor vehicles whose various fan flaps, in part, must be displaced only into an open and into a closed end position, but in part must also be adjusted steplessly over a certain pivot or slide range. If vacuum-actuated single-acting adjusting motors are now provided for the adjustment of the fan flaps, then the same must be acted upon with vacuum from a vacuum installation, for example, by way of solenoid directional control valves, respectively, must be vented again. A large number of magnetically actuated directional control valves is required for such a motor vehicle-air-conditioning installation which, however, must be installed for the most part under very constricted space conditions.
It is desirable to be able to accommodate all magnetic directional control valves near one another and protected against mechanical damage.
A directional control valve component assembly far-reachingly satisfying such requirements is already known (DE-OS No. 32 18 006). In this prior art the directional control valves are individually plugged-in at a common base element with simultaneous fluidic and electrical contact-making, however, without any further protection against mechanical damages and loosening. Furthermore, each individual directional control valve includes a load connection piece, with which a vacuum line is connected. With a careless attachment of the vacuum line, for example, after a valve exchange, a damaging of the fluidic or especially of the electric plug-in connection cannot be precluded.
It is the object of the present invention to so construct a directional control valve component assembly of the aforementioned type that--with the use of air as working medium--it can be installed in a simple but operationally reliable manner.
The underlying problems are solved according to the present invention in that the electric printed circuit board (PC board) is additionally constructed as carrier of the directional control valves electricaly and mechanically securely connected therewith and is fixed by the plugging-in thereof into the plug-in receptacles of the base element, in that contours corresponding with one another are provided at the cover and at the base element for the formation and sealing of a pneumatic main channel extending through the housing during the fastening of the cover at the base element, whereby a feed connection piece arranged outside at the housing and the feed connection paths of a group of first directional control valves terminating in a surface of the base element delimiting the main channel are connected by the main channel, in that additionally support elements for fixing the position of the directional control valves and/or the electrical PC board are provided at the cover, and in that feed connection paths of a group of second directional control valves not connected with the main channel terminate open toward the atmospheric pressure at another surface of the base element.
The electrical connections of the directional control valves are initially peened or bent over with the corresponding contacts on the electrical PC board, which is mechanically rigidly constructed, and additionally are soldered together. A stable arrangement results therefrom which can be plugged together as a whole with the base element while establishing the fluidic contact between the directional control valves and their connecting paths. A groove-like channel is provided in the base element which is closed off by a cover covering off the directional control valves and the PC board. An elastic seal for the channel is integrated into the cover.
Additional assembly and manufacturing operations (for example, drilling or shaping operations) are avoided with this arrangement of the pneumatic main channel. Thus, the open groove can be provided considerably more simply in a plastic injection-molded part than a long tunnel bore which requires the forming-out of a corresponding core. Furthermore, also branch bores or channels can be provided in a more simple and precise manner. Additionally, the directional control valves and the PC board can be secured in position against loosening out of the plug-in receptacles by further support elements integrated into the cover.
It is necessary for the stepless adjustment of a singly operating vacuum-adjusting motor to alternately vent or evacuate the pressure chamber thereof.
In an advantageous construction of the directional control valve component assembly in accordance with the present invention, the connection of such a vacuum-adjusting motor is made possible by way of only a single pressure line which is connected to a common load connection path of two 2/2 directional control valves.
In that connection, it is known (DE-OS No. 30 47 209) to provide two 2/2-directional control valves of similar construction in the housing of a steplessly adjustable vacuum-adjusting motor whose two load connection paths terminate separately from one another directly in the pressure chamber of the vacuum-adjusting motor. However, this prior art provides no indication for the construction of a directional control valve component assembly in the form claimed herein.
In a further advantageous construction according to the present invention, two mutually oppositely disposed rows of plug-in receptacles are provided in the base element. It is possible by axial offset of the plug-in receptacles of the two rows to limit the width of the base element because the plug-in receptacles, which are formed-in as recesses, can overlap in the projection along the base element without being fluidically connected with each other.